TO kill weeds, wheat farmers in Australia spray the herbicide
24D. Unfortunately, the herbicide also kills cotton plants, which
are often planted in nearby fields.
By genetically modifying the cotton plant, however, scientists at
the Commonwealth Scientific and Industrial Research Organization
(CSIRO) have increased the cotton's tolerance to the herbicide
almost 50 times. Next year, CSIRO will begin field-testing the
The cotton modification is one of several ways Australia is
working to improve its farms with genetic engineering.
"This is powerful technology, and it is an area in which
Australian science is in many cases one jump ahead of the rest of
the world," says John Stocker, chief executive of CSIRO.
The Genetic Manipulation Advisory Committee (GMAC), a private
clearinghouse, has approved seven genetically modified organisms for
use in Australia. Many more genetic modifications are being
developed in the laboratories and will soon be field-tested.
Although there are no national numbers on the amount spent on
genetic research, CSIRO estimates it is now spending annually $32
million (US), or 7 percent of its total budget, on genetic research.
CSIRO, a mainly government-funded research arm, is the largest
science organization involved in the research.
Some of the most fundamental research is taking place at the
University of Adelaide, where scientists are trying to control the
activity of any gene that can be placed in an animal. For example,
scientists know that growth hormones help livestock grow.
"The question is, can we put in a gene that will do the job
instead of administering the growth hormone externally," says Julian
Wells, director of the Special Research Center in Gene Technology at
The first animals Dr. Wells worked on are pigs, termed "super
pigs" because of their ability to grow more efficiently and have
less fat than normal pigs. Wells says super pigs are still five to
10 years away from being commercially available. "It is important to
get it right before commercialization," he says.
Many modifications involve Australia's main crops - wheat and
wool. In July, GMAC approved a CSIRO "tracking" technique for
genetically tagging soil bacteria that can reduce take-all disease
in wheat. Take-all can decrease wheat yields by more than 50
percent, depending on the weather. Although the soil bacteria is
natural, the scientists needed to see if it would migrate into the
water supply or to other areas. As a result of the genetic tagging,
CSIRO reported, "There is little chance of it moving into the water
system or affecting other soil processes."
A professor at the University of Adelaide is now trying to change
the genes of sheep so they produce more wool. To grow wool, a sheep
needs sulfur. Much of the sulfur in its food is digested in a
pre-stomach, however, and is not available to the animal. By
changing a gene, scientists hope to allow the sheep to use more
sulfur. This process has not been cleared with GMAC for release but
is being tested on laboratory mice. At the same time, scientists are
trying to increase the amount of sulfur produced by alfalfa, known
as lucerne in Australia.
Sheep growers also have a problem with the salmonellosis virus
when shipping live sheep for export. "Exporters have lost 1/3 of
their sheep," says Merilyn Sleigh, assistant chief at CSIRO's
division of biomolecular engineering in North Ryde, a Sydney suburb.
Through genetic manipulation, CSIRO's McMaster Laboratory has
produced a vaccine for the sheep. Ms. Sleigh says the initial test
was successful and the vaccine has been cleared by GMAC for release.
Australian scientists have also genetically modified a virus used
for vaccinating cattle to prevent feedlot animals from getting
bovine rhinotracheitis, a respiratory disease. …